FR3129090A1 - Device for treating an air flow - Google Patents

Abstract

The invention relates to a device (1) for treating a gas stream, for example air, comprising a means for dispersing a liquid (6) in the form of droplets, preferably in the form of micro-droplets, in said gas flow to be treated, and an ultraviolet treatment means configured to subject said gas flow to be treated to UV rays. The UV treatment means is positioned downstream of the means for dispersing a liquid (6) in the form of droplets, and the UV treatment means is mounted inside a liquid-gas separation means (10 ) so as to separate the liquid present in the gas stream when the gas stream to be treated is subjected to UV rays. Figure for abstract: Fig. 1.

Description

Device for treating an air flow

The present invention relates to the field of devices for treating a gas, and more particularly the field of devices for treating air by injecting liquid into the gas stream to be treated.

There are devices for processing a gas stream. In such devices, as described for example in documents FR 2 452 311 or US 2021/252447, a liquid is introduced into the gas stream, in the form of droplets, in order to capture the dust and particles present in the gas stream, then the liquid, with the dust and particles captured, is separated from the gas flow.

More specifically, such devices involve the coating of dust with the liquid and are generally intended for the purification of industrial fumes which must be cleared of their harmful dust before being evacuated in the open air.

In such devices, water is sprayed at high pressure into the converging part of a venturi fed by the gas to be treated. This spraying makes it possible to obtain very fine droplets whose probability of collision with the dust is increased thanks to the effects of turbulence generated by the venturi.

However, such devices, intended for the treatment of industrial fumes in particular, remain cumbersome, and not entirely satisfactory in their efficiency of treatment of the air flow.

There are also air treatment devices comprising a sterilization device configured to eliminate pathogenic germs, in particular using ultraviolet (UV). Such a device is described in particular in document WO 2021/148211 and comprises a UV module positioned upstream of the introduction of the liquid into the gas stream.

However, and as for the previous documents, such a device remains cumbersome, and does not give complete satisfaction in terms of air flow processing efficiency.

There is thus a need to have a device for processing an efficient and compact air flow, in particular for use in a public space, in particular an enclosed space, such as interior or underground spaces for which the space available for such a device remains reduced.

The present invention aims to solve the various technical problems mentioned above. In particular, the present invention aims to provide a device for processing a gas stream, in particular an air stream, which is compact and efficient. The present invention also aims to provide a device for treating a gas flow suitable for treating the air present in a given space, in particular confined.

Thus, according to one aspect, there is proposed a device for processing a gas stream, for example air, comprising a means for dispersing a liquid in the form of droplets, preferably in the form of micro-droplets, in said gas stream to be treated, and ultraviolet treatment means configured to subject said gas stream to be treated to UV rays. The UV treatment means is positioned downstream of the means for dispersing a liquid in the form of droplets, and the UV treatment means is mounted inside a liquid-gas separation means so as to separate the liquid present in the gas stream when the gas stream to be treated is subjected to UV rays.

The liquid-gas separation means, with the integrated UV treatment means, makes it possible to simultaneously carry out two treatment operations on the gaseous flow: the gaseous flow is on the one hand dissociated from the liquid which it contains, in particular by centrifugation , and on the other hand treated with UV radiation to destroy certain pathogens, in particular pathogenic germs.

The liquid-gas separation means therefore makes it possible to make the air treatment device more compact. Furthermore, the combination of liquid-gas separation may require a relatively long presence time of the gas stream in the liquid-gas separation means, allowing an even more effective action of the UV treatment means.

Finally, such combined means intervene at the end of the gas flow treatment process, that is to say after the treatment by dispersion of liquid droplets in the gas flow, and just before the release of the treated gas flow outside of the processing device. UV radiation is therefore used to kill only the microorganisms remaining in the gas stream, and not all those present in the gas stream entering the treatment device according to the invention.

Preferably, the liquid-gas separation means is configured to separate the liquid contained in the gas stream by centrifugation, and the UV treatment means is positioned in the middle of the path traveled by the gas stream to be treated in the liquid separation means -gas.

Separation by centrifugation makes it possible for the gas stream with liquid droplets to take a longer path during which the separation between the liquid and the gas takes place. Such an extended path makes it possible in particular to lengthen the duration of exposure to the UV radiation emitted by the UV treatment means positioned in the middle of such an extended path.

Preferably, the liquid-gas separation means is configured to guide the gas stream to be treated along a helical trajectory, for example according to a cylindrical helix or according to a conical helix, and the UV treatment means is positioned along the axis of said helical trajectory.

The helical trajectory of the gas flow with liquid droplets allows a so-called "cyclone" separation in which the fluids to be separated are driven along a helical trajectory similar to a whirlpool during which the centrifugal force applied to the various fluids present leads to a separation of the fluids in question according to their density, or density. This results in not only an effective separation of the liquid present in the gas, but also a longer duration of exposure of the gas to UV radiation.

Preferably, the liquid-gas separation means is oriented substantially vertically, with the inlet of the gas stream to be treated at the bottom, and the outlet at the top.

The vertical orientation of the liquid-gas separation means makes it possible to directly and easily recover the liquid at the bottom of the separation means.

Preferably, the means for dispersing a liquid comprises a constriction forming a venturi, and a liquid introduction nozzle arranged in or close to the constriction forming a venturi, for example a ring with one or more orifices for the centripetal introduction of a liquid, mounted in the narrowing forming venturi.

The means of dispersion of a liquid can be a Venturi, that is to say a narrowing of the circulation section of the gas flow so as to obtain a higher speed and a lower pressure. It is then possible to inject a liquid into it to form droplets, or even micro-droplets, in the gas stream. In particular, the injection of a liquid into the gas stream makes it possible to collect, within the liquid, the particles and dust present in the gas stream. Furthermore, the injection of droplets, or even micro-droplets, makes it possible to increase the specific contact surface between the liquid and the gas, in the gas stream, and therefore to increase the possibilities of capturing said particles or dust.

Preferably, the means for dispersing a liquid is oriented substantially vertically, with the inlet of the gas stream to be treated at the top and the outlet at the bottom.

The vertical orientation, downwards, of the dispersion means, in particular in combination with the vertical orientation, upwards, of the separation means, makes it possible to make the gas flow to be treated travel through a U-shaped path in the middle of which it is possible to provide one and the same liquid recovery means. Such a vertical U-shaped path thus leads to reducing the size of the air treatment device, by pooling certain common elements used at different times of the treatment.

Preferably, the treatment device comprises a means for collecting and storing the liquid to be dispersed in the gaseous flow to be treated and/or separated from the gaseous flow to be treated, the collection and storage means comprising for example a lower part with the liquid , in communication with an upper part with air, the collection and storage means, for example the upper part, being positioned downstream of the dispersion means and upstream of the separation means.

Preferably, the path traveled by the air flow in the treatment device has a general U shape, with the collection and storage means being in the lower part of the U, and the dispersion means and the separation means each forming a branch of the U.

Such a configuration makes it possible to improve the recovery of the liquid by the means of collection and storage, in particular by gravity. In particular, the collection and storage means can recover by gravity the liquid coming from the means for dispersing a liquid and the means for liquid-gas separation.

Preferably, the liquid dispersed in the form of droplets comprises microorganisms, preferably microalgae.

In order to limit the size of the air treatment device, the liquid used to capture the dust and particles present in the gas flow is the same as the liquid to treat said particles and dust thus captured. More specifically, the air treatment device directly uses the liquid with microorganisms to supply the means for dispersing a liquid in the gas stream. Once separated, these droplets of liquid comprising microorganisms, dust and particles, are then redirected to the culture tank where the rest of the liquid with microorganisms is located, to be treated, with a longer treatment time. long, said dust and particles. There is therefore no dilution effect of the liquid comprising microorganisms, by continuous addition of water droplets. In addition, there is an optimization of the means used in the air treatment device and its size, by using the same liquid at different stages of treatment of the gas flow.

Preferably, the liquid dispersed in the form of droplets comprises micro-algae, and the collection and storage means comprises means for developing the micro-algae, preferably lighting means.

In order to promote the formation and proliferation of microorganisms, the collection and storage means may comprise lighting means, preferably arranged vertically and distributed in the microorganism development liquid.

Preferably, the lighting means are positioned substantially vertically in the liquid, and the collection and storage means also comprise bubbling means mounted at a lower end of the lighting means and configured to cause air bubbles to circulate along along an outer wall of the lighting means.

In order to limit the formation of a biofilm on the surface of the lighting means, which could reduce their effectiveness, and allow microorganisms to mix, the treatment device also includes bubbling means.

Preferably, the bubbling means comprise nozzles, preferably conical, configured to release a substantially rectilinear stream of bubbles, preferably one behind the other.

According to one aspect, a bubbling means is also provided. The bubbling means includes mounting means at a lower end of a lighting means, and is configured to concentrate and release bubbles along the exterior wall of the lighting means.

The bubbling means may comprise an air inlet, a means for forming bubbles, for example a porous material, connected to the air inlet, a frame with in particular a means for concentrating bubbles mounted above the means bubble forming means, and the mounting means to an illuminating means positioned above the bubble concentrating means.

Preferably, the bubble concentration means has the shape of a truncated cone whose lower section is configured to receive the bubble forming means, and the upper section, of smaller size than the lower section, is configured to receive the mounting means.

The bubbling means comprises in particular one or more openings, for example above the bubble concentration means, in particular at the level of the mounting means, allowing the release of the bubbles along the lighting means.

Such a bubbling means makes it possible in particular to form a flow of bubbles capable of coming to scrape the outer surface of the lighting means, to remove or avoid the deposits of biofilm on the latter, and to allow a mixing of the microorganisms present in the liquid.

There schematically represents a device for processing an air flow according to the present invention;

There shows a sectional view, from the side, of a liquid-gas separation means for the treatment device of the ; And

There represents an exploded view, in perspective, of a bubbling means according to the present invention.

Claims (11)

Device (1) for treating a gas flow, for example air, comprising a means for dispersing a liquid (6) in the form of droplets, preferably in the form of micro-droplets, in the said gas flow to be treated , and ultraviolet treatment means (28) configured to subject said gas stream to be treated to UV rays, characterized in that the UV treatment means (28) is positioned downstream of the means for dispersing a liquid (6) in the form of droplets, and in that the UV treatment means (28) is mounted inside a liquid-gas separation means (10) so as to separate the liquid present in the flow gas when the gas stream to be treated is subjected to UV rays. Treatment device (1) according to claim 1, in which the liquid-gas separation means (10) is configured to separate the liquid contained in the gas stream by centrifugation, and in which the UV treatment means (28) is positioned in the middle of the path traveled by the gas stream to be treated in the liquid-gas separation means (10). Treatment device (1) according to claim 1 or 2, in which the liquid-gas separation means (10) is configured to guide the gas flow to be treated along a helical path, for example according to a cylindrical helix or according to a conical helix. , and wherein the UV treatment means (28) is positioned along the axis (A) of said helical path. Treatment device (1) according to any one of the preceding claims, in which the liquid-gas separation means (10) is oriented substantially vertically, with the inlet of the gas stream to be treated at the bottom, and the outlet at the top. Treatment device (1) according to any one of the preceding claims, in which the means for dispersing a liquid (6) comprises a constriction (18) forming a venturi, and a liquid introduction nozzle (20) arranged in or close to the constriction (18) forming the venturi, for example a ring with one or more orifices for the centripetal introduction of a liquid, mounted in the constriction (18) forming the venturi. Treatment device (1) according to the preceding claim, in which the means for dispersing a liquid (6) is oriented substantially vertically, with the inlet of the gas stream to be treated at the top and the outlet at the bottom. Treatment device (1) according to any one of the preceding claims, comprising means for collecting and storing (8) the liquid to be dispersed in the gaseous flow to be treated and/or separated from the gaseous flow to be treated, the means for collecting and storage (8) being positioned downstream of the dispersion means (6) and upstream of the separation means (10). Treatment device (1) according to any one of the preceding claims, in which the liquid dispersed in the form of droplets comprises micro-organisms, preferably micro-algae. Treatment device (1) according to Claims 7 and 8, in which the liquid dispersed in the form of droplets comprises micro-algae, and in which the means for collecting and storing (8) comprises means for developing the micro-algae , preferably lighting means (29). Treatment device (1) according to the preceding claim, in which the lighting means (29) are positioned substantially vertically in the liquid, and in which the collection and storage means (8) also comprise bubbling means (30 ) mounted at a lower end of the lighting means (29) and configured to circulate air bubbles along an outer wall of the lighting means (29). Treatment device (1) according to the preceding claim, in which the bubbling means (30) comprise nozzles (36), preferably conical, configured to release a substantially rectilinear stream of bubbles, preferably one behind the other.